Maple tree named ‘INAG-E61’

ABSTRACT

A new and distinct variety of Maple tree being small to moderate-sized with red leaves, hardy in USDA Zones 4 to 8, and having an upright, narrow, oval habit, is disclosed.

Genus and species: Acer pseudosieboldianum x Acer palmatum.

Denomination: ‘INAG-E61’.

BACKGROUND

‘INAG-E61’ is a new and distinct variety of Maple tree. ‘INAG-E61’ originated from a tree breeding program started in 1997 with the goal of expanding the cold tolerance range of Japanese Maple trees to include USDA Zone 4. The focus has been on red foliage color.

The general term “Japanese maples” applies to species, forms, and cultivars within Section and Series Palmata including native Japanese species Acer palmatum, japonicum, shirasawanum, and sieboldianum and two not native species, the West Coast North American species Acer circinatum or Vine maple and Acer pseudosieboldianum or Korean maple.

Acer pseudosieboldianum is the foundation breeding genetics used for enhancing hardiness. This species is native from the Korean peninsula north into the biodiverse forested Ussuri river region of Eastern China and Russia, a region spared from past glaciation enabling long periods of uninterrupted species development from a former warm climate to the current cold dry winter climate. Acer pseudosieboldianum successfully grows in the Upper Midwest region of USDA zone 4 with some seedling and cultivar success in USDA zone 3. Besides hardiness, Korean maple has features of sun tolerant vibrant green summer foliage, outstanding multicolored fall foliage, but as a garden tree the typically marcescent leaves and coarse, open, erratic branching and unpredictable habit is a detraction.

The species native to Japan: Acer palmatum, japonicum, shirasawanum, and sieboldianum have long been garden worthy trees with hundreds of years of human selection and refinement. These species and selected cultivars are USDA Zone 5 or 6 or 7 and as such are either marginal or not hardy as garden trees for much of North America, hence, the breeding combination of superior garden quality Japanese maple trees crossed with the cold hardy genetics from Acer pseudosieboldianum.

In 1997, a controlled breeding program was started in a greenhouse in Boring, Oreg. using Korean maple seedlings (female parent) with Acer palmatum ‘Nuresagi’ unpatented (male parent). ‘Nuresagi’ is an upright Japanese maple tree with deep-purple-red, palmate, 5-7 lobed leaves, and hardy to USDA Zone 5. Seedlings from this cross were grown and evaluated with one seedling designated ‘E7’ showing red pigmented new growth that matures green. ‘E7’ was propagated and later named NORTH WIND ‘Is1NW’ (not patented). This cultivar has been found to be USDA Zone 4 hardy, but the red color needed further improvement. In spring 2006 NORTH WIND ‘Is1NW’ was used as the female seed parent for ‘INAG-E61’ and was open-pollinated. The male parent is unknown but adjacent to the female parent tree were three same-aged, red-leafed hybrid selections identified as ‘E3’, ‘E4’, and ‘E26’. Seeds from the open-pollination were collected Fall 2006 and planted April 2007 and germinated June 2007. The best seedlings from this cross were grown for long term evaluation in a testing location in Boring, Oreg. In July 2016 ‘INAG-E61’ was first identified. First hardiness screening test December 2016.

‘INAG-E61’ was first propagated by grafting in August 2016 onto Acer palmatum seedling rootstock (unpatented). ‘INAG-E61’ reproduces true to type in successive generations of asexual reproduction via grafting onto Acer palmatum seedling rootstock (unpatented).

SUMMARY

The following are the most outstanding and distinguishing characteristics of this new variety when grown under normal horticultural practices in Boring, Oreg.

-   -   1. A small to moderate-sized Maple tree with red leaves;     -   2. Hardy to USDA Zones 4 to 8; and     -   3. Having an upright, narrow, oval habit.

DESCRIPTION OF THE PHOTOGRAPHS

This new Acer tree is illustrated by the accompanying photographs which show the plant's overall plant habit including form, trunk, and foliage. The photographs were taken outdoors in Boring, Oreg. with dates indicated. The colors shown are as true as can be reasonably obtained by conventional photographic procedures.

FIG. 1 shows a 6-year-old tree of ‘INAG-E61’ in the foreground on May 26, 2022.

FIG. 2 shows a close-up of the spring foliage and the flowers of a 5-year-old tree of ‘INAG-E61’ on May 7, 2021.

FIG. 3 shows a close-up of the immature spring foliage with pubescence of a 5-year-old tree of ‘INAG-E61’ on Apr. 29, 2021.

FIG. 4 shows a close-up of the summer foliage of a 14-year-old tree of ‘INAG-E61’ on Jun. 24, 2021.

FIG. 5 shows the progression of the foliage color of a 5-year-old tree of ‘INAG-E61’ from April to August 2021.

FIG. 6 shows a close-up of the bark from a 15-year-old tree of ‘INAG-E61’ on Sep. 7, 2022.

FIG. 7 show a close-up of the samara from a 12-year-old tree of ‘INAG-E61’ on Aug. 2, 2019.

FIG. 8 shows a whole 4-year-old tree of ‘INAG-E61’, including the fall foliage on Oct. 19, 2021.

FIG. 9 shows a close-up of the fall foliage Oct. 19, 2021 of the tree of FIG. 8 .

DETAILED DESCRIPTION

The following detailed descriptions are for the distinctive characteristics of ‘INAG-E61’. The data which define these characteristics were collected outdoors in Boring, Oreg. in August 2022 (unless noted) on 6-year-old and 15-year-old trees in Boring, Oreg. Color references are to The R.H.S. Colour Chart of The Royal Horticultural Society of London (R.H.S.) 2001, except where general terms of ordinary dictionary significance are used.

-   Classification:     -   -   Family.—Sapindaceae.         -   Botanical.—Acer pseudosieboldianum x Acer palmatum.         -   Denomination.—‘INAG-E61’. -   Tree:     -   -   Type.—Deciduous.         -   Shape.—Upright, narrow, oval.         -   Growth and branching habit.—Small to moderate-sized single             stem garden tree; upright, and slightly spreading;             well-ordered branch pattern; full-leafed tree.         -   Propagation type.—Grafting onto seedling Acer palmatum             rootstock (unpatented).         -   Height (from soil line).—280 cm at 15 years and 190 cm at 6             years.         -   Width (horizontal plant diameter).—180 cm at 15 years and             120 cm at 6 years.         -   Growth rate.—25 cm per year.         -   Hardiness.—Hardy from USDA Zones 4 to 8.         -   Time to produce a finished tree.—Trees are sellable at 4             years, but will also be sold at 6, 8, or 10-years-old.         -   Diameter of the trunk measure at 10 cm from the soil             line.—10.5 cm at 15 years and 4.0 cm at 6 years.         -   Trunk bark smooth at 6 years to slightly textured at 15             years.—Small 0.1 cm to 0.4 cm wide scale-like plates RHS             156C (Greyed-White) that are variable in length and             vertically arranged with jagged edges, plates separated by             fissures; at 6 years fissures 0.1 cm to 0.2 cm wide and             paper shallow deep, and at 15 years fissures 0.2 cm to 0.5             cm wide by up to 0.5 cm deep, fissures revealing             darker-colored RHS 165B (Greyed-Orange) underlayment; no             lenticels observed on the trunk. -   Foliage:     -   -   Arrangement.—Opposite and simple.         -   Quantity of leaves per lateral branch.—Upper crown, strong             lateral branches: Average is 10, 12, 14 leaves, or             occasionally more. Mid-crown, moderate-sized lateral             branches: Average is 6 or 8 leaves. Lower-level lateral             branches: 4 or 2 leaves.         -   Shape.—Palmatilobed; 7 lobed, but occasionally, there are 9             lobes; lobes are deeply divided ½ to ¾ of the leaf.         -   Apex.—Narrowly acuminate; long, sharp leaf tip.         -   Base.—Truncate to subcordate.         -   Margin.—Doubly serrate.         -   Length.—7 cm to 10 cm.         -   Width.—7 cm to 13 cm.         -   Texture (summer leaf).—Upper surface: Smooth, mid-veins             slightly sunken. Lower surface: Smooth, mid-veins             protruding.         -   Pubescence.—Present on new foliage.         -   Color, observed in August 2022.—Immature, new leaves, both             upper and lower surfaces: RHS 53A (Red). Mid-shoot, mature             leaf color, both upper and lower surfaces: RHS N77A             (Purple). Oldest sun-exposed leaves: Upper surface: RHS             N189A (Greyed-Green). Lower surface: RHS 147B             (Yellow-Green). Fall color, observed in October 2021, upper             surface: Early onset and multicolored; RHS 58B (Red-Purple),             RHS 51A (Red), RHS 30B (Orange-Red) and RHS 17C             (Yellow-Orange).         -   Petiole.—Length: 4 cm to 7 cm. Diameter: 0.1 cm. Color:             Immature or exposed upper leaf petiole: RHS 53A (Red).             Mature or shaded leaf petiole: RHS N144A (Yellow-Green).         -   Leaf bud.—General: Hidden under the leaf petiole. Color: RHS             N144A (Yellow-Green). Shape: Conical. Height and width: 0.1             cm and 0.1 cm.         -   Venation pattern.—Palmate, mid-lobe veins with paired             forward-angled lateral veins and smaller reticulate veins.         -   Venation color.—Immature color is RHS 153A (Yellow-Green)             and mature is RHS N144A (Yellow-Green); Venation color             changes from immature to mature leaf and is always a lighter             color compared to the base leaf color; the yellow-green             highlighted venation pattern provides a glowing optic with             sunlight transmission. -   Lateral branches/stems:     -   -   Quantity per tree (6-year-old tree).—30 lateral branches             arising from the trunk.         -   Color.—Color gradient is from red to yellow-green; new or             sun-exposed branch surfaces are red and transitioning to             yellow-green on shaded or aged surfaces. 1-year-old branch,             sun-exposed: RHS 187B (Greyed-Purple). 1-year-old branch,             mid-shoot or with some shading: RHS 181C (Greyed-Red).             1-year-old branch, base of shoot or lower shaded surface:             RHS N146A (Yellow-Green). 2-year-old branch: RHS N146A             (Yellow-Green).         -   Size.—Upper crown, 1-year-old shoot: 45 cm in length and 0.5             cm in width with 7 nodes. Mid crown, 1-year-old shoot: 30 cm             in length and 0.3 cm in width with 5 to 6 nodes. Small,             secondary 1-year-old shoot: Less than 30 cm in length and             0.1 cm in width with 1 to 3 nodes.         -   Internode length.—4 cm to 9 cm.         -   Texture.—Smooth.         -   Lenticels.—Are not a distinct visual feature; occur at the             base of strong 1-year-old shoots and 2- and 3-year-old             branches and are not observed on the trunk; are small, less             than 0.1 cm to 0.2 cm, circular and/or diamond-shaped;             lenticels have RHS 155C (White) rings surrounding a very             small, and short protuberance RHS 17B (Yellow-Orange) as             observed under a lens. -   Flowers: Observed but not a defining characteristic of the tree. -   Fruit: Each paired samara (wing and nut) is 1 cm to 1.5 cm in length     and 0.5 cm to 1 cm in width with a rounded wing tip; pairs held at a     wide obtuse angle 130 to 160°. Samara wing color RHS 144A     (Yellow-Green) and wing edge RHS 64C (Red-Purple). The nutlet is     very hard, round to oblong, 0.5 cm in width and RHS 144A     (Yellow-Green). Often, only 1 of the paired nutlets has a fully     developed embryo; the underdeveloped embryo has a flattened nutlet     and an undersized or less than half-sized attached wing. -   Disease/pest resistance: No specific disease or pest resistance has     been observed to date.

COMPARISON WITH PARENTAL, COMMERCIAL AND ACER PSEUDOSIEBOLDIANUM AND ACER PALMATUM LINES

Table 1 shows a comparison of the differences between ‘INAG-E61’ and the commercial Maple tree ‘Bloodgood’ (unpatented).

TABLE 1 Comparison with Commercial Line Characteristic ‘INAG-E61’ ‘Bloodgood’ Hardiness USDA Zones 4 to 8 USDA Zones 5 to 8 Leaf lobes 7-lobed 5-lobed (occasionally 9) (occasionally 7) Leaf margins Doubly serrate Serrate Leaf venation color, RHS N144A (Yellow- RHS 59B (Red-Purple) mature Green) Trunk 15 years Slight texture, fissures, Smooth, no no lenticles fissures, lenticles Samara 1 cm to 1.5 cm length 2.5 cm to 3 cm and 0.5 cm to length and 1 cm wide 1 cm wide

Table 2 shows a comparison of differences between ‘INAG-E61’ and the parental lines and Table 3 shows comparison between a typical Acer pseudosieboldianum and Acer palmatum.

TABLE 2 Comparison with Parental Lines Female parent: Male parent- NORTH WIND open Characteristic ‘INAG-E61’ ‘IslNW’ pollinated Hardiness zones USDA Zones 4 to 8 USDA Zones 4 to 8 Not available Leaf color, RHS N77A (Purple) RHS 146A Not available mature (Yellow-Green)

TABLE 3 Comparison with Acer pseudosieboldianum and Acer palmatum Acer pseudo- Characteristic ‘INAG-E61’ sieboldianum Acer palmatum Hardiness zones USDA Zones USDA Zones USDA Zones 4 to 8 3 to 8 5 to 8 Leaf color, mature RHS N77A RHS 137A RHS 147 (Purple) (Green) (Yellow-Green) Leaf lobes 7 to 9 9 5 Trunk Fissured Fissured Smooth Fall leaf drop Yes No, usually yes marcescent 

I claim:
 1. A new and distinct variety of Maple tree designated ‘INAG-E61’ as illustrated and described herein. 